Taking their lead from jessamyn, Apple has included a warrant canary in their transparency report.
"Apple has never received an order under Section 215 of the USA Patriot Act. We would expect to challenge such an order if served on us."jessamyn created the warrant canary in response to the USA Patriot Act, which permits warrantless searches of library records and prohibits the library from making the existence of these searches known. It does not explicitly prohibit the library from stating that it has not received any secret search warrants. To the best of my knowledge, this is the first use of a warrant canary by a big, high-profile organization. Nice work, jessamyn!
In light of the latest news reports, I was curious... Has Metafilter ever received a National Security Letter or a FISA court surveillance warrant? Hundreds of thousands of NSL's and tens of thousands of FISA warrants have been handed out to various websites and organizations over the past decade. A single order can encompass multiple individuals' records. MetaFilter's members include several well known "people of interest" in the security and infosec world, including some who have been targeted with NSL's through other online providers, such as Google. Unfortunately, it is illegal to answer "yes" to this question; however, if a mod would like to answer "no comment" or perhaps just not answer this thread at all, as opposed to giving a flat "no, never", I'm sure we could draw our own conclusions. Also, given that Jessamyn was the creator of the original library warrant canary, does MeFi as a site have a similar warrant canary? If not, did it ever? (See also: "My National Security Letter Gag Order", posted in 2007 and Jessamyn's blog about librarians who successfully challenged a NSL.)